Om my 305 I bored it .060 over with the XE 262 cam with the dual plane intake and 600 cfm carb. Ran great and a little over 300 HP. Also ran a 3 deuce set up with 3 rochester carbs and that ran even better, but now am running 2 500 edelbrock carbs and have yet to test them. Probably toomuch carb but have to wait till spring to find out. I think the 305 is a great little engine and can be made to perform and keep up with your stock or slightly built 327 and some 350's. Course thats just my 2 cents.